Machines for coating a product in a band

ABSTRACT

The machine includes a heating drum and a press roller ensuring the deposition on the heating drum of the material intended for the coating. Cooling means for the press roller are provided to act from the outside over a fraction only of the cylindrical wall of the press roller. The machine enables the coating of a product in a band by a material which has to undergo a heat treatment.

United States Paten Gomarin et al. 14 1 Aug. 8, 1972 1 MACHINES FORCOATING A [56] References Cited [72] (;I BAND Ch UNITED STATES PATENTSnven ors: au Gomari Mame; Jean 1, fijgg fg g 3,239,367 3/1966 Demeter..1 18/202 f France 2,711,132 6/1955 Viscardi ..118/202 2,724,36211/1955 Burke et a1... ..118/202 [73] Pans 3,548,781 12/1970 l-lomungm,..118/202 [22] Filed: Aug. 3, 1970 Primary Examiner-Henry S. Jaudon 21APPL 0 357 Attorney-Larson, Taylor and Hinds [30] Foreign ApplicationPriority Data [57] ABS CT d d The machine includes a heating rum an apress I Aug. 7, France roller ensuring the deposition on the heatingdrum f the material intended for the coating. Cooling means 12?}ll'f'il':::1:J:iiiiiijjiiiiiijjijijiaa z53%;!11383 for the Press rollerare Provided to w from the 5 Field f Search 1 18202 24 2 2. 101/ 9 sideover a fraction only of the cylindrical wall of the v 1 1 2 pressroller. The machine enables the coating of a product in a band by amaterial which has to undergo a heat treatment.

7 Clains, '4 Drawing figures mimmms W2 3.632 133 SHEEI 1 [IF 2PATENTEDAus' 8 m2 SHEET 2 [IF 2 MACHINES FOR COATING A PRODUCT IN A BANDThe invention relates to machines for coating a product in a band bymaterial which has to undergo a heat treatment (plasticizing,polymerization, etc.), these machines being of the type which include arotary drum of which the cylindrical wall is heated, the band to becoated being applied on this cylindrical wall over The machine of thetype concerned includes cooling means for its press roller which arearranged so as to act from the outside over a fraction only of thecylindrical wall of the press roller, this fraction extending from thesupport zone of the press roller the heating drum up to a zone where thematerial intended for the coating is deposited on the press roller.

In a first embodiment according to the invention, these cooling meansare constituted by a blower device a fr nly of its Circumference, hmaterial for a cooling gas including a blower wall parallel to thetended for the coating being deposited on the said cylindrical wall by aroller rotating in reverse sense to the drum, (i.e. both clockwise orboth anticlockwise), parallel with this latter and applied against thesaid drum at the level of a support zone located in the remainingfraction of its circumference.

Such machines for coating are well known and are deslilgnated, in thetechnique, by the name Reverse- Ro In the following the rotary drum ofwhich the cylindrical wall is heated will be designated by heating drumand the roller ensuring the deposit of the material lilntended for thecoating will be designated by press to er.

The heating roller is constituted, at least as regards its cylindricalwall, by a metal hard and a good conductor of heat, such as steel, whilethe press roller is constituted, at least as regards its cylindrical.wall, by a deformable and elastic material such as rubber.

This press roller is applied against the heating drum so that thereexists between the press roller and the heating drum, not a contactgenerator, but a contact rectangle whose width can reach severalcentimeters.

It will then be seen that there is, at the level'of such a support zone,a transmission of heat by conduction between the heating drum and thepress roller, and that, failing special precautions, the cylindricalwall of this press roller is heated, which risks initiating the heattreatment of the material intended for the coating before the latter isdeposited on the cylindrical wall of the heating drum.

Now the fact this heat treatment takes place before the depositionspoils considerably the quality of the coating, especially from thepoint of view of its regularity and of its adherence.

To avoid this drawback, it is not possible technically to cool theheating drum between the zone where the product in a coated band leavesits cylindrical surface and the support zone of the press roller.Moreover, such a cooling would alter the homogeneity of heating of thematerial intended for the coating and its heat treatment would therebybe rendered more difficult.

It is also impossible to contemplate an internal cooling of the pressroller since, due to the fact of its mechanical properties ofdeforrnability and elasticity of its cylindrical wall, the latter isnecessarily constituted of a material of which the thermal coefficientof conductivity is low, which hence does not enable internal cooling ofthe press roller to be contemplated by circulation of a cooling fluid onthe inside of the said roller.

It is an object of the invention to provide cooling means for the pressroller which are efficient, simple, compatible with the characteristicsof the machine, and which do not introduce in practice any additionalcomplication in the operation, the maintenance and the adjustment of themachine.

cylindrical wall of the press roller between the support zone on theheating drum and the zone where the material intended for the coating isdeposited, this blower wall being provided with blower nozzles and withsuction nozzles for the evacuation of the cooling gas.

In a second embodiment according to the invention, these cooling meansare constituted by a plurality of rotary cooling rollers, arrangedparallel to the press roller and applied against the latter so as todefine a contact rectangle between each cooling roller and the pressroller, each cooling roller being hollow, constituted of a metal ofwhich the coefficient of conductivity is high, and traversed by acooling fluid (liquid or gas).

Thus, due to such cooling means, it is possible to cool the press rollerin a manner which is efficient, simple, compatible with thecharacteristics of the machine (especially as regards the prevention ofany direct contact between the outer surface of the cylindrical wall ofthe press roller and a liquid), and which does not introduce in practiceany additional complications in the operation, the maintenance and theadjustment of the ma chine.

On the latter point, it should be noted that the cooling means can bemounted in retractable manner to be spaced from the press roller (bypivoting or translation) at the time of operations, of maintenance andof adjustment of the machine.

The invention consists, apart from the features which have just beenconsidered, of certain other features which are used preferably at thesame time and which will be more explicitly considered below.

In order that the invention may be more fully understood, severalpreferred embodiments of machines according to the invention aredescribed below, purely by way of illustrative but non-limitingexamples, with reference to the accompanying drawings in which:

FIG. 1, shows a diagrammatic partial section of one embodiment of themachine for the coating of a product in a band, constructed according tothe invention;

FIG. 2 shows a section on a large scale illustrating a detail of theembodiment shown in FIG. 1;

FIG. 3 shows in partial section, a first embodiment according to theinvention; and

FIG. 4, lastly, shows a partial section of another embodiment accordingto the invention.

The machine for the coating of a product in a band 1 is shownschematically in FIG. 1.

This machine includes a rotary heating drum 2, with a horizontal axis.Heating means are provided so that the outer surface of the cylindricalwall of this heating drum 2 is brought to a given temperature which, asfar as possible, is homogeneous and constant over the said outersurface. The cylindrical wall of the heating drum 2 is hence of amaterial which is a good conductor of heat, and hard, for reasons whichwill appear clearly in the following. This material can be steel.

The temperature of the outer surface of the cylindrical wall of theheating drum 2 must be such that the material intended for the coatingand which is deposited on this cylindrical wall undergoes the desiredheat treatment to obtain the desired coated product.

The band 1 of product is applied on the cylindrical wall of the heatingdrum 2 over a fraction only of its circumference. According to theembodiment illustrated in FIG. 1, this fraction covers an angular rangeof about 250. Two return rollars 3 and 4 are provided at the two ends ofthis angular range to ensure the application of the band 1 on theheating drum 2.

The material 5 intended for the coating is deposited on the outersurface of the cylindrical wall of the heat-' ing drum 2 by a pressroller 6 rotating in reverse sense to the heating drum 2 (i.e. bothclockwise or both anticlockwise), parallel with the latter and appliedagainst the said heating drum 2 at the level of a support zone locatedin the remaining fraction of its circumference.

With reference to the first return roller 3 from which the product in aband 1 is applied on the heating drum 2, the support zone where thedeposition of the material 5 intended for the coating occurs, issituated about ahead of this first return roller 3.

The press roller 6 has a diameter distinctly less than the diameter ofthe heating drum 2 and it is constituted, at least as regards itscylindrical wall, by a deformable and elastic material. This materialcan be rubber.

As shown in FIG. 2, this press roller 6 is applied against the heatingdrum 2 so that there exists between the press roller 6 and the heatingdrum 2 a contact rectangle. By way of example, it should be indicatedthat for a diameter of 1,200 mm of heating drum 2 and of 250 mm for thepress roller 6, the width of this contact rectangle is 20 mm. In thisexample, the speeds of rotation (in reverse sense) of the heating drum 2and of the press roller 6 are such that the respective peripheraltangential speeds are 18 meters per minute and 21 meters per minute.

The material 5 intended for the coating is then deposited on the pressroller 6 by a first auxiliary roller 7, rotating in reverse sense to thepress roller 6, parallel with the latter and applied against the saidpress roller 6 at the level of a support zone diametrically opposite thesupport zone of the press roller 6 against the heating drum 2.

There is provided a second auxiliary roller 8, rotating in reverse senseto the first auxiliary roller 7, parallel with the latter and appliedagainst the said first auxiliary roller 7, the axes of the two abovesaidauxiliary rollers 7 and 8 being, approximately at least, in the samehorizontal plane.

1n the sense of rotation of the heating drum 2, a scraper blade 9 isprovided above one of the auxiliary rollers 7 or 8, this blade 9retaining the material 5 intended for the coating and which finds itselfabove the abovesaid auxiliary rollers 7 and 8 and between them. If thesense of rotation of the heating drum 2 is that indicated in FIG. 1,this blade 9 is above the second auxiliary roller 9.

The auxiliary rollers 7 and 8 are of steel and have advantageously thesame diameter as the press roller 6.

Their speeds of rotation are such that, in the case of the figuresindicated previously, the peripheral tangential speed of the firstauxiliary roller 7 is 21 meters per minute and that of the secondauxiliary peripheral roller 8 is 1 meter per minute.

In such a machine, the material 5 intended for the coating is depositedin the form of a sheet 5a on the first auxiliary roller 7, then thissheet 50 passes over the press roller 6 and finally on the heating drum2 where it becomes interposed under the band product 1 from the firstreturn roller 3.

This being the case and according to the main feature of the invention,the machine comprises cooling means 10 from the press roller 6 which arearranged so as to act from the outside over the fraction of itscircumference which extends from the support zone of the press roller 6on the heating drum 2 up to the support zone of the press roller 6 onthe first auxiliary roller 7.

By Way of example, it should be indicated that, for an apparatus whoseheating drum 2 has a diameter of 1,200 mm, the press roller 6 and thefirst auxiliary roller 7 a diameter of 250 mm, the support zones of thepress roller 6 on the heating drum 2 and on the first auxiliary roller 7are separated by an angilar distance of about 130to 150.

In the embodiment according to the invention illustrated in FIG. 3,these cooling means 10 are constituted by a blower device for coolinggas (air at ambiant temperature or previously cooled air). This blowerdevice includes a blower wall 1 1 parallel to the cylindrical wall ofthe press roller 6 between the support zone on the heating drum 2 andthe support zone on the first auxiliary roller 7. This blower wall 11 isprovided with blower nozzles 12 and with suction nozzle 12 for theremoval of the cooling gas. A supply caisson or tank 14 and anevacuation caisson or tank 15 enable respectively the supply of theblower nozzles 12 and evacuation from the suction nozzle 13.

Advantageously, the two ends of the blower wall 11 neighboring thesupport zone on the heating drum 2 and the support zone on the firstauxiliary roller 7 include suction nozzle 13.

With such cooling means supplied with air at 20 C and with a flow of2,500 m3/h, it is possible to maintain the temperature of thecylindrical wall of the press roller 6 at a value less than or at themost equal to 40C while the temperature of the cylindrical wall of theheating drum 2 is of the order of to C.

In the embodiment according to the invention illustrated in FIG. 4, thecooling means 10 are constituted by a plurality of cooling rollers 16,rotating, arranged parallel to the press roller 6 and applied againstthe latter so as to define a contact rectangle between each coolingroller 16 and the press roller 6.

Each cooling roller 16 is hollow and constituted of metal whosecoefficient of thermal conductivity is high, a cooling fluid, preferablya liquid, passing through each of the abovesaid cooling rollers 16.

As a result of which and whatever the embodiment adopted, there isprovided an apparatus for the coating of a'band product in which thecooling means for the press roller are efficient, simple, and avoid anyrisk of the commencement of thermal treatment of the material intendedfor the coating on the cylindrical wall of the press roller.

The coating is hence effected under good conditions of regularity and ofadherence.

Moreover, these cooling means are compatible with the characteristics ofthe machine, especially as regards the prevention of any direct contactbetween the outer surface of the cylindrical wall of the press rollerand a iquid.

Finally, these cooling means do not introduce in practice additionalcomplications in the operation, the maintenance and the adjustment ofthe machine.

As if self-evident and as emerges already besides from the precedingdescription, the invention is in no way limited to those of its methodsof application, nor to those of its methods of production of its variousparts, which have been more especially indicated; it embraces, on thecontrary, all variations.

We claim:

2. Machine according to claim 1, wherein the two ends of the blower wallneighboring the support zone and the feed zone include suction nozzles.

3. Machine according to claim 1, wherein said heating drum is of steeland said press roller is of rubber.

4. Machine according to claim 1, wherein said feed means comprise twoauxiliary rollers and a scraper blade.

1. Machine for coating a product in band form with a 5 material whichhas to undergo heat treatment, said machine comprising a rotary heatingdrum having a cylindrical wall, means for applying said band on saidcylindrical wall over a fraction only of its circumference, a pressroller arranged to deposit said material on said cylindrical wall, saidpress roller being arranged to rotate in reverse sense to, parallel withthe heating drum, and applicable against the heating drum at the levelof a support zone located in the remaining fraction of itscircumference, feed means for applying said material to the press rollerat a feed zone thereof, cooling means for the press roller arranged toact from the outside over a portion only of the cylindrical wall of thepress roller, said portion extending from said support zone up to saidfeed zone, said cooling means being constituted by a device for blowinga cooling gas, said device including a blower wall parallel to thecylindri- 5. Machine according to claim 4, wherein said auxiliaryrollers are of about the same diameter as the press roller.

6. Machine for coating a product in band form with a material which hasto undergo heat treatment, said machine comprising a rotary heating drumhaving a cylindrical wall,

means for applying said band on said cylindrical wall over a fractiononly of its circumference,

a press roller arranged to deposit said material on said cylindricalwall,

said press roller being arranged to rotate in reverse sense to, parallelwith the heating drum, and applicable against the heating drum at thelevel of a support zone located in the remaining fraction of itscircumference,

feed means for applying said material to the press rtfller at a fee zonethereof, coo ng means or the press roller arranged to act from theoutside over a portion only of the cylindrical wall of the press roller,said portion extending from said support zone up to said feed zone, saidcooling means being constituted by a plurality of cooling rollersarranged to rotate parallel to the press roller and applied against thelatter so as to define a contact rectangle between each cooling rollerand the press roller, each of said cooling rollers being hollow,constituted of a metal whose coefficient of thermal conductivity is highand adapted for the passage of a cooling fluid therethrough. 7. Machineaccording to claim 6, wherein said cooling fluid is a liquid.

1. Machine for coating a product in band form with a material which hasto undergo heat treatment, said machine comprising a rotary heating drumhaving a cylindrical wall, means for applying said band on saidcylindrical wall over a fraction only of its circumference, a pressroller arranged to deposit said material on said cylindrical wall, saidpress roller being arranged to rotate in reverse sense to, parallel withthe heating drum, and applicable against the heating drum at the levelof a support zone located in the remaining fraction of itscircumference, feed means for applying said material to the press rollerat a feed zone thereof, cooling means for the press roller arranged toact from the outside over a portion only of the cylindrical wall of thepress roller, said portion extending from said support zone up to saidfeed zone, said cooling means being constituted by a device for blowinga cooling gas, said device including a blower wall parallel to thecylindrical wall of the press roller between said support zone and saidfeed zone and suction nozzles for the removal of the cooling gas beingprovided in said blower wall, a supply tank and evacuation tank enablingrespectively the supply from the blowing nozzles and evacuation from thesuction nozzles.
 2. Machine according to claim 1, wherein the two endsof the blower wall neighboring the support zone and the feed zoneinclude suction nozzles.
 3. Machine according to claim 1, wherein saidheating drum is of steel and said press roller is of rubber.
 4. Machineaccording to claim 1, wherein said feed means comprise two auxiliaryrollers and a scraper blade.
 5. Machine according to claim 4, whereinsaid auxiliary rollers are of about the same diameter as the pressroller.
 6. Machine for coating a product in band form with a materialwhich has to undergo heat treatment, said machine comprising a rotaryheating drum having a cylindrical wall, means for applying said band onsaid cylindrical wall over a fraction only of its circumference, a pressroller arranged to deposit said material on said cylindrical wall, saidpress roller being arranged to rotate in reverse sense to, parallel withthe heating drum, and applicable against the heating drum at the levelof a support zone located in the remaining fraction of itscircumference, feed means for applying said material to the press rollerat a feed zone thereof, cooling means for the press roller arranged toact from the outside over a portion only of the cylindrical wall of thepress roller, said portion extending from said support zone up to saidfeed zone, said cooling means being constituted by a plurality ofcooling rollers arranged to rotate parallel to the press roller andapplied against the latter so as to define a contact rectangle betweeneach cooling roller and the press roller, each of said cooling rollersbeing hollow, constituted of a metal whose coefficient of thermalconductivity is high and adapted for the passage of a cooling fluidtherethrough.
 7. Machine according to claim 6, wherein said coolingfluid is a liquid.